In the last few decades, dual-fuel engines have gained widespread popularity owing to their efficient operation. As the name suggests, dual-fuel engines selectively operate on two fuels in order to optimize an operational efficiency. For example, nowadays, dual-fuel engines operating on a natural gas fuel and a diesel fuel are employed in locomotives. Such dual-fuel engines usually include separate conduits for supplying the diesel fuel and the natural gas fuel to fuel injectors. For example, the natural gas fuel and the diesel fuel may be delivered to the fuel injectors through a first conduit and a second conduit, respectively. The dual fuel-engines may switch between the diesel fuel and the natural gas fuel to maintain a high operational efficiency.
When a dual-fuel engine is in a non-operational mode, i.e., when the dual-fuel engine is not operating, the natural gas in a high-pressure state stuck in the first conduit is released to atmosphere through an exhaust conduit. However, sometimes, due to leakage in the fuel injectors, the diesel fuel from the fuel injectors flows back and enters the first conduit. Therefore, the diesel fuel may also get released into the atmosphere through the exhaust conduit along with the natural gas. Such wastage of the diesel fuel and the consequential maintenance lead to a significant increase in operational cost of the dual-fuel engine.
German Patent Publication No. 102012206979 A1 (hereinafter the '979 publication), discloses a system having a separating device. The system has a fuel injector supplying fuel by a high pressure injection rail. The separating device is arranged in a line and separates fuel, e.g., diesel, and fluid, i.e., water, from each other. The fluid is restored into a fluid container by a return-flow pipe. A first valve is arranged between a fluid pump and a mixing device, a second valve is arranged between the high pressure injection rail and separating device, and a third valve is arranged between the separating device and fluid pump. The system of the '979 publication does not disclose a separating device for a dual-fuel engine.